EP3957306A1 - Composition comprising at least one glycosyl flavonoid and use thereof in cosmetics or dermatology - Google Patents

Abstract

The present invention relates to a cosmetic and/or dermatological composition comprising, as active ingredient, at least one glycosylated flavonoid, characterized in that it further comprises, as active ingredient, a compound capable of limiting or preventing the penetration into the keratinocytes of a polycyclic aromatic hydrocarbon of the benzo[a]pyrene, cyclopenta[c,d]pyrene, dibenzo[a,h]anthracene or dibenzo[a,l]pyrene type and/or a compound characterized by its ability to absorb blue light.

Description

Technical area

The present invention relates to compositions comprising at least one glycosylated flavonoid, which can be used in topical application, in the treatment of a non-allergic pathology causing the production of IL31, in particular a pathology affecting the skin and chosen from pruritus, atopic dermatitis , eczema, psoriasis, nodular prurigo.

Prior art

The skin is the main barrier that protects the human body from the environment. This environment is composed of exogenous factors that can cause physical, chemical or even biological stresses, which increase skin aging and the risk of developing skin pathologies of different degrees of severity. It is now accepted that pollution and solar radiation have a synergistic and negative effect on the skin ( The skin aging exposome, Krutmann J. et al. Dermatol Sci. 2017 Mar; 85(3):152-161 ).

Pollution can take different forms: atmospheric pollution, water pollution, global warming (thermal pollution), chemical pollution through industries or components of everyday objects (paint, solvent, glue, etc.).

Solar radiation composed of visible light, UVA/UVB, but also blue light, leads to the production of inflammatory cytokines of the IL-1, IL-6, IL-8 type. Other recent studies show that blue light, emitted by the sun but also by all lighting devices such as computers, tablets, televisions, mobile phones, has an influence on photoaging, by increasing the level of internal free radicals in the level of keratinocytes and melanocytes. This would also lead to the formation of pigment spots ( Duteil et al, Differences in visible light-induced pigmentation according to wavelengths: a clinical and histological study in comparison with UVB exposure, Pigment Cell Melanoma Res, 2014 vol. 27(5) p. 822-6T ).

Atmospheric pollution also plays an important role in skin pathologies, and in particular polycyclic aromatic hydrocarbons (PAHs) which come from the combustion of wood, but especially in urban environments from exhaust gases. In a recent study, researchers showed, on human skin explants, that the metabolization of PAHs leads to the production of easily eliminated metabolites, but that a small fraction reacts with DNA to induce mutations. This study also shows that exposure to solar UV rays reduces the ability of skin cells to metabolize PAHs, which could thus accumulate in the tissues ( Metabolism and genotoxicity of polycyclic aromatic hydrocarbons in human skin explants: mixture effects and modulation by sunlight, Anne von Koschembahr et al., Archives of Toxicology volume 94, pages 495-507(2020 ); Solar simulated light exposure alters metabolization and genotoxicity induced by benzo[a]pyrene in human skin, Anne von Koschembahr et al., Scientific Reports volume 8, Article number: 14692 (2018 )).

Decreased metabolism could lead to benzo[a]pyrene (B[a]P) accumulation and long-term toxicity.

Some skin pathologies do not have an inflammatory component, such as pruritus for example, which nevertheless is characterized by the secretion of certain cytokines such as IL-31 (Interleukin 31) ( IL-31 is crucial for induction of pruritus, but not inflammation, in contact hypersensitivity, Ayako Takamori et al., Sci Rep (2018) 8:6639 ).

IL-31 is a cytokine of the IL-6 family, produced by activated CD4+ T lymphocytes, suggesting its involvement in the development of a Th2 type immune response. It has been demonstrated that mice transgenic for IL-31 develop inflammatory skin of the atopic dermatitis type. Furthermore, Il-31 seems to be responsible for pruritus.

There are different ways to treat itching, especially itching induced by increased IL-31 production. Anti-IL-31 therapeutic antibodies have been developed and are used in the treatment of pruritus or atopic dermatitis, such as nemolizumab, an antibody developed by Galderma in clinical trials in moderate to severe atopic dermatitis. Other anti-IL-31 antibodies have been described ( US10273297 , EP2734549 ), for their use in this scope. Nevertheless, treatments with therapeutic antibodies are not without side effects, since they are not specific for the IL-31 produced by the keratinocytes of the skin. Moreover, these treatments are expensive. Thus, there is a real need for a solution making it possible to attenuate the production of IL-31 in the keratinocytes by a treatment at the local level.

The inventors first observed that the production of IL-31 by human keratinocytes was increased after exposure to PAHs in synergy with exposure to blue light.

The inventors have, surprisingly, demonstrated that compounds of the glycosylated flavonoid type make it possible to reduce the production of IL-31 by the keratinocytes, induced by exposure to PAHs and to blue light.

Technical problem to solve

An object of the present invention is to provide cosmetic and/or dermatological compositions making it possible to reduce the production of IL-31 in the skin and to treat or prevent a pathology affecting the skin, chosen from pruritus, atopic dermatitis , eczema, psoriasis, nodular prurigo.

Detailed description of the invention

An object of the present invention is to provide a cosmetic and/or dermatological composition comprising, as active ingredient, at least one glycosylated flavonoid, characterized in that it further comprises, as active ingredient, a compound capable of limit or prevent the penetration into the keratinocytes of a polycyclic aromatic hydrocarbon of the benzo[a]pyrene, cyclopenta[c,d]pyrene, dibenzo[a,h]anthracene or dibenzo[a,l]pyrene type and/or a compound characterized by its ability to absorb blue light.

The term "cosmetic composition" means any substance or composition intended to be brought into contact with the various superficial parts of the human body (epidermis, hair and capillary systems, nails, lips and external genital organs) or with the teeth and oral mucous membranes , with a view, exclusively or mainly, to cleaning them, perfuming them, modifying their appearance, protecting them, keeping them in good condition or correcting body odours.

The term "dermatological composition" means any substance or composition intended for treating or preventing skin conditions or for regular skin care.

The term "active ingredient" means a natural or chemical substance, extracted or synthetic, entering into the formulation of a therapeutic or cosmetic composition, characterized in that it has a beneficial effect, treatment or prevention on a pathology or a symptom.

The term "flavonoid" means any compound belonging to the family of flavonoids, characterized by the same basic structure formed by two aromatic rings linked by three carbons: C6-C3-C6, divided into classes which are flavones, flavonols, flavononols or dihydroflavonols, flavanones, aurones, chalcones and dihydrochalcones.

The term “glycosylated flavonoid” means any compound belonging to the classes described above, bearing at least one sugar chosen from glucose, galactose, rhamnose. The flavonoids according to the invention are natural or synthetic flavonoids. Flavonoids are naturally present in fruits, vegetables, tea, wine, but also in certain medicinal plants such as hawthorn, ginkgo, passion flower, peppermint, artichoke, or neem, guava , but also many other plants and flowers (non-exhaustive list). It is possible to extract them. Many protocols have been published and are accessible to those skilled in the art.

In one embodiment of the invention, the composition according to the invention further comprises, as active ingredient, a compound capable of limiting or preventing the penetration into the keratinocytes of a polycyclic aromatic hydrocarbon of benzo [a]pyrene, cyclopenta[c,d]pyrene, dibenzo[a,h]anthracene or dibenzo[a,l]pyrene.

The term “limit or prevent the penetration into the keratinocytes of a polycyclic aromatic hydrocarbon of the benzo[a]pyrene, cyclopenta[c,d]pyrene, dibenzo[a,h]anthracene or dibenzo[a,l]pyrene type” , the ability of any substance to maintain PAH-type polluting agents on the outer surface of the skin. In other words, limiting or preventing the penetration into the keratinocytes of a PAH amounts to maintaining the keratinocytes in their state of physiological equilibrium, that is to say when the structure and the functions are not altered, that they do not show characteristics or markers of inflammation such as the synthesis and release of cytokines such as TNF alpha for example ( The influence of PM2.5 on lung injury and cytokines in mice. Yang J, et al., Exp Ther Med. 2019 Oct,18(4):2503-2511 ). This extremely aggressive interleukin causes degradation of membranes and skin cells responsible for inflammation and aging of the skin ( Wang Y., et al., Mech Aging Dev. 2019 Dec, 184:111160 ). Polycyclic aromatic hydrocarbons, also called PAHs, are of the benzo[a]pyrene (C ₂₀ H ₁₂ ), cyclopenta[c,d]pyrene (C ₁₈ H ₁₀ ), dibenzo[a,h]anthracene (C ₂₂ H ₁₄ ) type. or dibenzo[a,l]pyrene (C ₂₄ H ₁₈ or C ₂₄ H ₁₄ ) or derivatives of these compounds. These compounds are generated by the combustion of fossil materials (in particular by diesel engines) in gaseous or particulate form. PAHs are therefore particularly present in urban air pollution.

The passage of hydrocarbons in the human organism takes place by inhalation, by ingestion, but also by transfer through the skin. Indeed, the inventors have shown in work preceding this invention, that the exposure of human keratinocytes to PAHs increases the production of IL-31 at the level of the keratinocytes.

In one embodiment of the invention, the composition according to the invention may also comprise a compound characterized by its ability to absorb blue light.

The term "ability to absorb blue light" means the ability of any substance to prevent the negative effects of blue light on skin aging and skin alterations, by limiting the exposure of the skin to said blue light.

Blue light between 400 and 500 nanometers (nm) in wavelength is part of the visible light spectrum which is between 400 and 800 nm. It is emitted by solar irradiation but also by all electronic devices with a screen based on Light Emitting Diodes (also called LEDs) such as smartphones, tablets, televisions or computers.

The energy emitted by this blue light can be close to 40 J/cm ² for solar irradiation and 10 J/cm ² for the screens of electronic devices.

In a preferred embodiment, the glycosylated flavonoid is a glycosylated flavonol. Flavonols constitute a class of flavonoids characterized by a phenol function at C3 and a C=O carbonyl function at C4 on the central heterocycle of the basic skeleton of flavonoids. Glycosylated flavonols can be in the form of mono, di or triglycosides. Among the monoglycosides are astragalin (kaempferol containing a glucose at R3), azalein (azaleatin containing a rhamnose at R3), hyperoside (quercetin containing a galactose at R3), isoquercitin (quercetin containing a glucose in R3), myricitrin (myricetin containing a rhamnose in R3), quercitrin (quercetin containing a rhamnose in R3), rutoside (quercetin containing a rutinose in R3), xanthorhamnine (rhamnetin containing a triholoside in R3), amurensin (kaempferol containing a glucose at R7 and a tert-amyl alcohol at R8), spiraeoside (quercetin containing a glucose at R4') and troxerutin (quercetin containing a rutinose at R3 and 3 hydroxyethyl).

Among the diglycosides are kaempferitrin (kaempferol containing a rhamnose at R3 and a rhamnose at R7), robinin (kaempferol containing a robinose at R3 and a rhamnose at R7), icariin (kaempferide containing a rhamnose at R3 and a glucose at R4 and a prenyl group and a methoxyl group). In a preferred embodiment, the glycosylated flavonoid is rhamnosylated or glucosylated, preferably rhamnosylated.

In a preferred embodiment, the rhamnosylated flavonoid is chosen from myricitrin (5,7-dihydroxy-3-[(2S,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxan-2 -yl]oxy-2-(3,4,5-trihydroxyphenyl)chromen-4-one), quercitrin (2-(3,4-Dihydroxyphenyl)-5,7-dihydroxy-3-[[(2S,3R ,4R,5R,6S)- 3,4,5-trihydroxy-6-methyl-2-tetrahydropyranyl]oxy]-4-chromenone), kaempferitrin (C ₂₇ H ₃₀ O ₁₄ ), azaleine (2-( 3,4-dihydroxyphenyl)-7-hydroxy-5-methoxy-3-[(2S,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxychromen-4- one), icariin (5-Hydroxy-2-(4-methoxyphenyl)-8-(3-methylbut-2-enyl)-7-[(2S,3R,4S,5S,6R)-3,4, 5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-3-[(2S,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxychromen- 4-one) or a mixture of at least two of these compounds. The mixture may consist of myricitrin and quercitrin, or myricitrin and kaempferitrin or myricitrin and azalein, or myricitrin and icariin, or quercitrin and azalein, or quercitrin and icariin, or azalein and icariine. The mixture may also consist of three rhamnosylated flavonoids such as myricitrin, quercitrin and azalein, or myricitrin, quercitrin and icariin, or myricitrin, kaempferitrin and azalein, or myricitrin, azalein and icariin or quercitrin, azalein and icariin for example. The list is not exhaustive.

In a preferred embodiment, the rhamnosylated flavonoid is myricitrin. In one embodiment of the invention, the compound capable of limiting or preventing the penetration into the keratinocytes of a polycyclic aromatic hydrocarbon of the benzo[a]pyrene, cyclopenta[c,d]pyrene, dibenzo[a, h]anthracene or dibenzo[a,l]pyrene is chosen from polysaccharides, cyclic polysaccharides of cyclodextrin type, emulsifiers, lipophilized hyaluronic acid.

The skin is made up of different layers and different cell types. The outermost layer, the epidermis, is made up of keratinocytes, melanocytes and Langerhans cells. This epidermis is broken down into four layers, characterized by the level of maturity of the keratinocytes that compose them. From innermost to outermost, the layers are: basal layer, Malpighian layer, granular layer, and stratum corneum. This stratum corneum is a hydrophobic barrier, which performs the barrier function necessary for the protection of the skin. Given the hydrophobic nature of the stratum corneum, lipophilic substances such as polycyclic aromatic hydrocarbons can easily penetrate into the keratinocytes.

Polysaccharides, also called glycans, polyosides, polyholosides or complex carbohydrates, are polymers of the carbohydrate family made up of several oses linked together by osidic bonds.

Polysaccharides have hydrophilic properties. Because of this, and because of the hydrophobic nature of PAHs, these polysaccharides create a hydrophilic physical barrier against the penetration of these substances.

The polysaccharides used in the context of the invention may be cyclic polysaccharides of the cyclodextrin type which include alpha-cyclodextrin (α-cyclodextrin, C ₃₆ H ₆₀ O ₃₀ ), beta-cyclodextrin (β-cyclodextrin, C ₄₂ H ₇₀ O ₃₅ ), gamma-cyclodextrin (γ-cyclodextrin, C ₄₈ H ₈₀ O ₄₀ ). Cyclodextrins are known to form a molecular cage that allows various molecules to be encapsulated. They are widely used in the food and pharmaceutical industries. Their natural origin is an asset. In the context of the present invention, cyclic polysaccharides of the cyclodextrin type participate in the capture of PAHs by their “hydrophobic cage” type molecular structure at the heart of the cyclic form of the polymer (6 to 9 residues) of glucose.

Cyclodextrins, hydrophobic on the inside, hydrophilic on the outside, capture molecules of the PAH type and create a molecular trap for said PAHs.

Thus, one of the subjects of the invention is a composition comprising, as active ingredient, at least one glycosylated flavonoid, more particularly myricitrin, quercitrin, azaleine, icariine or a mixture of at least two of these compounds and a cyclodextrin.

In the context of the invention, compounds capable of limiting or preventing the penetration into the keratinocytes of a polycyclic aromatic hydrocarbon are emulsifiers. An emulsifier is a compound capable of creating an emulsion. Any emulsifier has a hydrophilic end and a hydrophobic end, making possible mixtures of hydrophilic and hydrophobic substances. Polycyclic aromatic hydrocarbons are by nature, lipophilic and hydrophobic.

The addition to the composition of the invention of a compound of cyclodextrin type aims to create an emulsion between a PAH or a mixture of PAHs and a hydrophilic compound, in order to limit or prevent penetration into the keratinocytes. of said PAHs.

The emulsifiers which can be used in the context of the composition of the invention are: lecithin, phospholipids, lanolin or beeswax (natural emulsifiers), glycerol stearate, polysorbate 60 and the mixture of PEG-6/ PEG32/Glycol Stearate sold under the name Tefose ^® 63, glycolipids of the sophorolipid type or the octylglucoside of saponins, lipoproteins (non-exhaustive and non-limiting list).

Thus, one of the subjects of the invention is a composition comprising, as active ingredient, at least one glycosylated flavonoid, more particularly myricitrin, quercitrin, azaleine, icariine or a mixture of at least two of these compounds and an emulsifier.

In the context of the invention, a compound capable of limiting or preventing the penetration into the keratinocytes of a polycyclic aromatic hydrocarbon is also lipophilized hyaluronic acid.

Lipophilized hyaluronic acid has lipophilic and hydrophilic amphiphilic properties as an emulsifying base. This molecule captures lipophilic molecules such as B[a]P in the fatty chains that make up the lipophilized part. Thus, one of the subjects of the invention is a composition comprising, as active ingredient, at least one glycosylated flavonoid, more particularly myricitrin, quercitrin, azaleine, icariine or a mixture of at least two of these compounds and lipophilized hyaluronic acid.

In one embodiment of the invention, the compound capable of absorbing blue light is chosen from carotenoids or melanoidins.

Carotenoids include molecules from the carotene and xanthophyll families. The main carotenoids are astaxanthin, lycopene, beta-carotene, lutein and zeaxanthin. Carotenoids are fat-soluble and have recognized antioxidant and photoprotective properties. Thus, carotenoids can be used in the composition according to the invention, for their ability to absorb blue light ( Blue-Violet Light Irradiation Dose Dependently Decreases Carotenoids in Human Skin, Which Indicates the Generation of Free Radicals. Vandersee S. et al., Oxidative Med Cell Longev. Volume 2015, Article ID 579675 ).

Thus, one of the subjects of the invention is a composition comprising, as active ingredient, at least one glycosylated flavonoid, more particularly myricitrin, quercitrin, azaleine, icariine or a mixture of at least two of these compounds and a cyclodextrin or an emulsifier or lipophilized hyaluronic acid, and a carotenoid.

Melanoidins are heterogeneous brown polymers of high molecular weight which are formed during the Maillard reaction, by combination between sugars and amino acids. Due to their structure and chromophore properties (absorb in wavelengths from 400 to 500 nm) they are good filters for blue light. ( Coffee melanoidins: structures, mechanisms of formation and potential health impacts, Moreira AS, et al., Food Funct. 2012 Sep;3(9):903-15 ) .

Thus, one of the subjects of the invention is a composition comprising, as active ingredient, at least one glycosylated flavonoid, more particularly myricitrin, quercitrin, azaleine, icariine or a mixture of less two of these compounds and a cyclodextrin or an emulsifier or lipophilized hyaluronic acid, and a compound of the melanoidin family.

In one embodiment of the invention, the composition of the invention is formulated for topical application.

The compositions which can be used in the invention may be in any galenic form conventionally used for topical application and in particular in the form of an aqueous, alcoholic or aqueous-alcoholic solution or suspension or of an oily suspension or of a solution or a dispersion of the lotion or serum type, of an emulsion of liquid or semi-liquid consistency of the milk type, obtained by dispersing a fatty phase in an aqueous phase (O/W) or vice versa (W/O), or a suspension or emulsion of soft consistency of the cream (O/W) or (W/O) type, or of an aqueous or anhydrous gel, of an ointment, of a loose or compacted powder to be used as it is or to incorporate in an excipient, or in the form of microcapsules or microparticles, or of vesicular dispersions of the ionic and/or nonionic type.

In a known manner, the composition according to the invention may also contain adjuvants usual in the cosmetic, pharmaceutical or dermatological field, such as hydrophilic or lipophilic gelling agents, hydrophilic or lipophilic active agents, preservatives, antioxidants, solvents, perfumes , fillers, filters, bactericides, odor absorbers and colorants. A person skilled in the art knows how to choose the adjuvants and their quantity according to the galenic form desired.

In a preferred embodiment of the invention, the composition according to the invention is formulated in the form of a mist as described in Example 8.

In one embodiment, the invention relates to a glycosylated flavonoid compound, preferably a rhamnosylated flavonol, for its use in the treatment of a non-allergic pathology causing the production of IL31, in particular a pathology affecting the skin and chosen from pruritus, atopic dermatitis, eczema, psoriasis, nodular prurigo.

The term "treatment" means the attenuation or disappearance of at least one symptom of the pathology, which may be the reduction in the production of IL-31 by the keratinocytes, the reduction in susceptibility to scratching, the reduction in inflammation of the skin and until the disappearance of the symptom(s).

The inventors have shown that the exposure of human keratinocytes to PAHs and/or blue light leads to an increase in the production of IL-31 by said keratinocytes. In addition, authors have shown that itchy skin in pruritus or atopic dermatitis is associated with this production of IL-31 ( New mechanism underlying IL-31-induced atopic dermatitis, Meng J. el al., J Allergy Clin Immunol. 2018 May;141(5):1677-1689 ; IL-31: A new key player in dermatology and beyond, Baǧci IS et al., J Allergy Clin Immunol. 2018 Mar;141(3):858-866 ). One of the objects of the invention relates to a glycosylated flavonoid compound, preferably a rhamnosylated flavonol, for its use in the treatment of a non-allergic pathology causing the production of IL-31, in particular a pathology affecting the skin and chosen from pruritus, atopic dermatitis, eczema, psoriasis, nodular prurigo.

Pruritus is clinically defined as the subjective and unpleasant sensation of a desire to scratch. There is a sensory component beginning in the skin, which travels through the dorsal ganglia and is processed in the central nervous system. Often the motor reaction follows in the form of a desire to scratch. Scratching damages the skin and triggers an inflammatory reaction, which makes the itch even worse.

Atopic dermatitis, also called atopic eczema, is a chronic inflammatory disease of the skin. It develops preferentially in infants and children, but can persist and sometimes appear in adolescents and adults. It is characterized by skin dryness (xerosis) associated with eczema-type lesions (redness and itching, vesicles, oozing and crusts) which develop in flare-ups.

Eczema is a syndrome, a set of clinical signs and symptoms common to several conditions, which may correspond to several inflammatory skin diseases. These diseases are characterized by itching (pruritus), congestive redness of the skin (erythema) and rashes.

Psoriasis is a chronic inflammatory disease characterized by well-defined, red, raised plaques covered with whitish scales or a thin silvery film that peels off easily.

Prurigo or nodular prurigo is a dermatosis (skin disease) characterized by pruritic (itchy) lesions, some excoriated and/or associated with scratching streaks, accompanied by fierce itching that can affect sleep. Scratching maintains the lesions which become scabbed. A distinction is made between acute prurigos (lasting less than 6 weeks) which are most often secondary to insect bites, and chronic prurigos which can be of dermatological, neurological, psychiatric or systemic origin.

In a preferred embodiment of the invention, the rhamnosylated flavonol used for the treatment of a non-allergic pathology causing the production of IL31, in particular a pathology affecting the skin and chosen from pruritus, atopic dermatitis, eczema, psoriasis, nodular prurigo, is chosen from myricitrin, quercitrin, kaempferitrine, azaleine, icariine or a mixture of at least two of these compounds. The mixture may consist of myricitrin and quercitrin, or myricitrin and azalein, or myricitrin and icariin, or quercitrin and azalein, or quercitrin and icariin, or azalein and icariin. The mixture may also consist of three rhamnosylated flavonoids such as myricitrin, quercitrin and azalein, or myricitrin, quercitrin and icariin, myricitrin, azalein and icariin or quercitrin, azalein and the icariin.

Description of figures

• the figure 1 presents a cell viability test, measuring the percentage of viable cells, human keratinocytes, placed in the presence of myricitrin at different doses;
• the figure 2 shows the effect on IL-31 production by human keratinocytes of alphabenzopyrene, alone or in combination with blue light. Exposure to blue light is expressed in Joule per square centimeter (J/cm ² ). Exposure to alphabenzopyrene is expressed in micromolar (µM);
• the picture 3 presents the effect of myricitrin on keratinocytes previously exposed to alphabenzopyrene and to blue light on the release of IL-31 in pg/ml;
• the figure 4 represents IL31 concentrations, normalized by the amount of total cellular protein, illustrating the effects of asthaxanthin alone compared to the effects of myricitrin alone, after exposure of keratinocytes to blue light and benzo-a-pyrene;
• the figure 5 represents the value of inhibition of the release of IL31 for two concentrations of myricitrin and astaxanthin.

EXAMPLES Example 1: Culture of human keratinocytes

The cells used in this study are primary cultures of normal human keratinocytes (KHN) extracted after skin surgery from a 30-year-old donor.

They were cultured in KSFM complete medium: Keratinocyte-SFM (17005-31, Gibco) with L-Glutamine, supplemented with recombinant human epidermal growth factor (EGFhr, 10450-013, Gibco), bovine pituitary extract ( BPE, 13028-014, Gibco) and 1% streptomycin penicillin (15070-063, Gibco) at 37° C. under an atmosphere of 5% CO ₂ up to 80% confluence.

Example 2: Keratinocyte Viability Test

On D0, the normal human keratinocytes are incubated in 96-well plates in a culture medium. The cells are left to stabilize for 24 hours at 37° C. in an atmosphere plus 5% CO ₂ , as described in example 1.

On D1, the cells are treated with myricitrin, dissolved in the culture medium, at different concentrations. The culture is maintained for 24 hours at 37° C. and 5% CO ₂ . Viability of KHN was assessed using Cell Proliferation Kit II (XTT) (11465015001, Roche) according to manufacturer's instructions.

The XTT system, a colorimetric method, is a test to quantify mitochondrial activity. This method, which is simple, precise and allows reproducible results, can be used as a viability test. This test is based on the cleavage of the yellow tetrazolium salt XTT into orange formazan, by the “succinate-tetrazolium reductase” system present in the mitochondrial respiratory chain of cells. Thus, the conversion occurs only in metabolically active cells, which means living cells.

The derived formazan is measured spectrophotometrically (at 450 nm with 650 nm reference). For each condition, averages of optical density data (OD, absorbance) are calculated.

The viability of the treated cells is expressed as a percentage of the untreated control: a treatment which decreases the viability of the cells, below the limit of 80% of mitochondrial activity compared with the untreated control, is considered to be cytotoxic for the cells. On the contrary, an increase in data is a sign of mitochondrial activity and possibly even a sign of cell proliferation. The keratinocytes cultured according to Example 1 are exposed to a range of myricitrin ranging from 0.21 to 50 μM. The Control Control represents the culture medium without adjuvant. The control+10% DMSO represents a toxic medium, witness to cellular toxicity. Experience shows that myricitrin has no toxic effect on keratinocytes.

Example 3: Use of a flavonoid, of the rhamnosylated flavonol type, on keratinocytes in culture

The keratinocytes cultured according to Example 1 are exposed either to alphabenzopyrene (B[a]P) at 20 μM), or to blue light (450 nm) at 40J/cm ² , or to the combination of two at the same doses. A treatment with myricitrin in an amount ranging from 10 μM to 50 μM is applied to cells which have previously received the combination B[a]P and blue light.

After 24 hours of treatment, an assay of the interleukin 31 (IL-31) released by the cells is carried out, via an immunoassay kit (ELISA). The IL-31 assay was performed with the human IL-31 ELISA MAXTM Deluxe Set (445704, Biolegend).

The combination of alphabenzopyrene and blue light induces an increase of IL-31 by the keratinocytes of +111%. The experiment shows that the addition of myricitrin from 20 μM induces a reduction in the production of IL-31 by -100% on cells pretreated with 20 μM B[a]P and blue light at 40J/cm ² .

Example 4: Use of a flavonoid, of the rhamnosylated flavonol type in patients On a panel of volunteers working in an urban environment [women aged 20 to 60 of Caucasian and Asian type] having problems of skin discomfort on the face (itching, pruritus, etc.) the cream of example 5 is applied to the half-face and to the other part of the face a placebo cream without the myricitrin.

Upon application and for eight days of use morning and evening, the volunteers give their organoleptic sensations-freshness, softness and ease of application of the products, as well as physiological sensations such as calm, cessation of itching, via a questionnaire to to fill. Statistical analyzes are carried out at the end of the test to demonstrate the effectiveness of the product containing myricitrin.

Example 5: Calming and softening cream for urban skin or skin prone to itching.

A-Aqueous phase

Glycerin 2.0%, Hexylene glycol 3.0%, Xanthan gum 0.5%, Myricitrin 0.5%, Preservatives qs (sufficient quantity), Carbomer 0.35%, NaOH 0.35%, Water qsp.100%

B-Fat Phase

Squalane 15%, Cetyl alcohol 2%, Arachidyl alcohol/behenyl alcohol/arachidylglucoside 1%, Glycerol stearate 5%, Preservative and fragrance qs

Example 6: Soothing moisturizing cream intended for urban skin with atopic tendency

A-Phase Oily

Ceteareth-2 3.5%, Ceteareth-21 between 2 to 4%, Wheat germ oil 3%, Cyclomethicone 7%, Octyl Palmitate 8%

B-Aqueous phase

Glycerin 7.0%, Hexylene glycol 3.0%, Preservatives qs, Water qsp.100%

C-Ingredients added in the emulsion, at a temperature below 40°C

Sodium Hyaluronate 0.1%, Myricitrin 1.0%, Water 5%, Tocopherol 0.05%, Vitamin A Palmitate 0.1%, Phospholipids 0.5%, Ceramides 3 0.1%, Polyacrylamide & C14- 13 isoparaffin & laureth-7 between 2 to 3.5%

Example 7: Cream and milk intended for skin exposed to blue light or presenting pigment spots.

A-Phase Oily

Glycerol monostearate 2%, PEG-100 stearate 3%, C12-C15 alkyl benzoate 10%, Dimethicone 5%, Tocopherol acetate 1%, Octyl-triazone (Uvinul T150) 1.5%, Butyl Methoxy Dibenzoyl methane (Eusolex 9020) 2.0 %, Cetostearyl alcohol 1%

B-Aqueous phase

Water qsp.100%, Quercitrin 0.5%, Preservatives 0.6%, Glycerin 7%, Hexylene glycol 3.0%, Carbomer 0.5%, Tetra sodium EDTA 0.2%, Sodium hyaluronate 0.1%, NaOH 0.5%, Preservative + perfume qs.

C-Ingredients added in the emulsion, at a temperature below 40°C

Tocopherol acetate between 0.1 to 1%, Pyridoxine between 0.01 to 0.05%, Vitamin A palmitate between 0.01 to 1%, d-Panthenol between 0.1 to 1%, Citric acid between 0, 1 to 0.5%, Zinc gluconate between 0.1 to 1%, Trisodium citrate between 1 to 2.5%, Water 5%.

Example 8: Protective mist for skin exposed to blue light from electronic devices

Water qsp. 100%, Kaempferitrin 2%, Preservatives 0.6%, Glycerin 7%, Hexylene glycol 3.0%, Carbomer 0.5%, Tetra sodium EDTA 0.2%, Sodium hyaluronate 0.1%, NaOH 0.5%, Preservative + perfume qs.

Example 9: comparison of the effects of astaxanthin and myricitrin on the release of IL31 by primary keratinocytes exposed to the combined effects of blue light and benzo-a-pyrene (BaP).

Astaxanthin (3,3'-dihydroxy-4,4'-dioxo-β-carotene) is a carotenoid, in particular synthesized by microalgae, this molecule absorbing wavelengths between 400 nm and 500 nm.

Benzo-a-pyrene ( CAS 50-32-8 ) is one of the most toxic PAHs (polycyclic aromatic hydrocarbons).

1. a) Type cellulaire : kératinocytes primaires d'épiderme humain (donneur 39 ans, ref : KER110, lot KER110049, Biopredic)
2. b) Conditions de culture : plaque 96-puits, 37°C, 5% CO₂, ensemencement 20.000 cellules/cm²
3. c) Milieu de culture : KSFM (Gibco ref : 10144892) + 1% pénicilline/streptomycine
4. d) Traitement avec les composés : effectué à 24h de l'ensemencement,
5. e) Temps d'incubation avec les composés : 24 heures de contact
6. f) Concentrations des composés testées : myricitrine et astaxanthine à 20µM et 50µM
7. g) Condition de stress : effectuée à la suite des traitements avec les composés ; exposition à l'irradiation (lumière bleue ; 40J/ cm² ; 450 nm) ; suivie par 24 heures de traitement avec 20µM benzo-a-pyrène (CRM40071, Sigma-Aldrich) en milieu de culture.

Cell treatments were performed as follows.

1. a) Cell type: primary keratinocytes from human epidermis (donor 39 years old, ref: KER110, lot KER110049, Biopredic)
2. b) Culture conditions: 96-well plate, 37°C, 5% CO ₂ , inoculation 20,000 cells/cm ²
3. c) Culture medium: KSFM (Gibco ref: 10144892) + 1% penicillin/streptomycin
4. d) Treatment with the compounds: carried out 24 hours after inoculation,
5. e) Incubation time with the compounds: 24 hours of contact
6. f) Concentrations of the compounds tested: myricitrin and astaxanthin at 20 μM and 50 μM
7. g) Stress condition: carried out following the treatments with the compounds; exposure to irradiation (blue light; 40J/cm ² ; 450 nm); followed by 24 hours of treatment with 20 μM benzo-a-pyrene (CRM40071, Sigma-Aldrich) in culture medium.

• Lot Contrôle : aucun traitement en dehors du renouvellement du milieu de culture
• Prélèvements :
  • Milieux de culture
  • Culots cellulaires
• End-points / read-out :
  • Dosage IL-31, à partir des milieux de culture (Human IL-31 ELISA MAX Deluxe ;
  • Biolegends)
  • Dosage des protéines totales, à partir des culots cellulaires (Méthode de Bradford)

The analyzes were carried out according to the following procedure.

• Control batch: no treatment except renewal of the culture medium
• Specimens :
  • Culture media
  • Cell pellets
• Endpoints / read-out:
  • IL-31 assay, from culture media (Human IL-31 ELISA MAX Deluxe;
  • Biolegends)
  • Assay of total proteins, from cell pellets (Bradford method)

Results: IL31 assay

In figure 4 , the results are expressed as IL-31 concentration normalized by the amount of total cellular protein.

In figure 5 , a release inhibition value (%) was obtained for the experimental groups, according to the following formula: $$\%\mathrm{Inhibition\; IL\; release}31:\%\mathrm{LotX}=\left(\mathrm{HE}31\mathrm{Stress}-\mathrm{HE}31\mathrm{Batch\; X}\right)/\left(\mathrm{<figure-callout\; id="31"\; label="HE"\; filenames="imgf0003.png"\; state="\{\{state\}\}">HE</figure-callout>}31\mathrm{Streets}-\mathrm{HE}31\mathrm{control}\right)\times 100$$

As a reference, the control group was considered at maximum efficiency (100%) and the stress group (Blue Light + BaP) at minimum efficiency (at 0%):

Claims (10)

Cosmetic and/or dermatological composition comprising, as active ingredient, at least one glycosylated flavonoid, characterized in that it further comprises, as active ingredient, a compound capable of limiting or preventing penetration into the keratinocytes of a polycyclic aromatic hydrocarbon of the benzo[a]pyrene, cyclopenta[c,d]pyrene, dibenzo[a,h]anthracene or dibenzo[a,l]pyrene type and/or a compound characterized by its ability to absorb blue light . Cosmetic and/or dermatological composition according to Claim 1, characterized in that the said glycosylated flavonoid is a glycosylated flavonol. Cosmetic and/or dermatological composition according to Claim 1 or 2, characterized in that the said glycosylated flavonoid is rhamnosylated or glucosylated, preferably rhamnosylated. Cosmetic and/or dermatological composition according to Claim 3, characterized in that the said rhamnosylated flavonoid is chosen from myricitrin, quercitrin, kaempferitrin, azaleine, icariine or a mixture of at least two of these compounds. Cosmetic and/or dermatological composition according to Claim 4, characterized in that the said rhamnosylated flavonoid is myricitrin. Cosmetic and/or dermatological composition according to any one of the preceding claims, characterized in that the said compound capable of limiting or preventing the penetration into the keratinocytes of a polycyclic aromatic hydrocarbon of the benzo[a]pyrene, cyclopenta[c ,d]pyrene, dibenzo[a,h]anthracene or dibenzo[a,l]pyrene is chosen from polysaccharides, cyclic polysaccharides of cyclodextrin type, emulsifiers, lipophilized hyaluronic acid. Cosmetic and/or dermatological composition according to any one of the preceding claims, characterized in that the said compound capable of absorbing blue light is chosen from carotenoids or melanoidins. Cosmetic and/or dermatological composition according to any one of the preceding claims, characterized in that it is formulated for topical application. Glycosylated flavonoid compound, preferably a rhamnosylated flavonol, for its use in the treatment of a non-allergic pathology giving rise to the production of IL31, in particular a pathology affecting the skin and chosen from pruritus, atopic dermatitis, eczema, psoriasis, nodular prurigo. Glycosylated flavonoid compound, preferably a rhamnosylated flavonol according to claim 9, chosen from myricitrin, quercitrin, kaempferitrin, azaleine, icariine or a mixture of at least two of these compounds.

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